Heat management system for a hybrid motor vehicle

Abstract

The invention relates to a thermal management system for a hybrid motor vehicle comprising at least one thermal engine and one electric motor (12), said system (10) comprising at least one first circuit (14) for cooling the thermal engine and a second circuit (16) for cooling at least the electric motor (12) and associated power electronics (18). The invention is characterized in that said second cooling circuit (16) comprises at least one heating radiator (20) for heating the interior of the passenger compartment of the vehicle.

Description

[0001] This application is a divisional application of the application filed on February 21, 2017, with application number 201780015073.X and entitled "A thermal management system, particularly for hybrid electric vehicles". Technical Field

[0002] The present invention relates to a thermal management system, particularly for hybrid electric vehicles.

[0003] More particularly, the present invention relates to a thermal management system for a hybrid motor vehicle comprising at least one thermal engine and one electric motor, said system comprising at least: - A first cooling circuit for cooling the vehicle's thermal engine by circulating at least one first coolant, and - A second cooling circuit for cooling at least the motor and the power electronic devices associated with the motor by circulating at least one second coolant. Background Technology

[0004] Examples of such thermal management systems (also known as thermal management systems) are known from the prior art, and these examples are specifically, but not exclusively, implemented in hybrid motor vehicles.

[0005] In the field of motor vehicles, the term "hybrid power" refers to a vehicle equipped with two types of drive systems that use two types of energy.

[0006] Hybrid vehicles typically include at least one thermal engine that provides the energy required for the vehicle's motion, and one or more electric motors that help optimize vehicle operation.

[0007] In a manner known per se, three main categories of drive systems can be identified in hybrid vehicles: “micro-hybrid,” “mild hybrid,” and “full hybrid,” with the classification of one of these categories determined by the power of the electric motor used.

[0008] There are many possible combinations for combining one or more electric motors with a heat engine, each with specific characteristics.

[0009] These "hybrid" vehicles are also known as "PHEVs" using the acronym "PHEV," which stands for Plug-in Hybrid Electric Vehicle.

[0010] The heating systems in hybrid vehicles are generally similar to those in combustion-powered vehicles, with the only difference being the hybrid operating mode. Heating activation is determined by the operation of the heat engine to provide the necessary calories to the engine's cooling circuitry.

[0011] A vehicle’s heating system typically includes at least one heating radiator (or “unit heater”) that is connected to the cooling circuit of the heat engine.

[0012] Unlike heat engines, electric motors are highly energy efficient, meaning that little or no energy (calories) can be used to heat the vehicle.

[0013] However, the desired improvement is in thermal management in such hybrid vehicles, and more specifically, in providing heating functionality in an optimal manner. Summary of the Invention

[0014] Specifically, the object of the present invention is to propose a novel design for a thermal management system for hybrid electric vehicles in order to improve the heating of the interior of the vehicle's passenger compartment while simplifying the thermal management system.

[0015] To this end, the present invention provides a thermal management system of the type described above, characterized in that the second cooling circuit is separate from the first cooling circuit and includes at least one heating radiator arranged in the second cooling circuit for heating the interior of the passenger compartment of the vehicle.

[0016] Advantageously, the first cooling circuit of the thermal engine (referred to as the high-temperature cooling circuit) and the second cooling circuit (referred to as the low-temperature cooling circuit), which is particularly associated with the electric motor, are separate from each other.

[0017] This design of the cooling system, with two separate, unconnected cooling circuits, further helps to promote degassing.

[0018] Because of this system, the calories generated by the heat engine during operation are recovered to heat the interior of the passenger compartment of the hybrid vehicle. Therefore, the calories recovered from the heat engine are added to the calories generated by the electric motor and the associated power electronics unit.

[0019] Advantageously, the at least one heating radiator (or “unit heater”) is arranged in a cryogenic second cooling circuit to selectively contribute to the function of heating the crew compartment.

[0020] The arrangement of the heating radiator (or “unit heater”) advantageously allows the cooling system, particularly the second cooling circuit (referred to as the cryogenic cooling circuit), to be simplified by reducing the number of necessary devices (e.g., solenoid valves, water pumps, degassing tanks, etc.).

[0021] Other features according to the invention: - The second cooling circuit includes at least one degassing tank, which is installed in parallel with the at least one heating radiator; - The first cooling circuit and the second cooling circuit of the thermal engine are selectively in heat transfer contact via at least one water / water heat exchanger; - The at least one water / water heat exchanger is installed such that it bypasses the second cooling circuit; - The second cooling circuit includes a heating device that is selectively controlled to heat the second coolant; - The heating device is arranged upstream of at least one heating radiator for heating the interior of the passenger compartment of the vehicle; - The second cooling circuit includes a device for measuring the temperature of the second coolant; - The second cooling circuit includes at least one cooling radiator and a branch bypassing the at least one radiator; - The second cooling circuit includes at least one circulator, which is arranged downstream of the cooling radiator; - The second cooling circuit includes a cooling loop for cooling at least one high-voltage battery associated with the motor via the second coolant. Attached Figure Description

[0022] Other features and advantages of the invention will become clearer upon reading the following description. For further understanding, please refer to... Figure 1 The accompanying drawings illustrate a portion of the thermal management system of a hybrid vehicle, and more specifically, a second cooling circuit including a unit heater according to an embodiment of the invention.

[0023] A single accompanying drawing schematically illustrates a thermal management system 10 (or thermal management system) for a hybrid electric vehicle (not shown). Detailed Implementation

[0024] This hybrid vehicle includes a thermal engine (not shown) and at least one electric motor 12.

[0025] The vehicle's thermal management system 10 includes at least a first cooling circuit 14 (referred to as a high-temperature cooling circuit) for cooling the vehicle's thermal engine by circulating at least one first coolant.

[0026] In the single accompanying figure, the cooling circuit 14 of the thermal engine is not shown in detail and is indicated schematically by arrows.

[0027] The vehicle’s thermal management system 10 includes a second cooling circuit 16 (referred to as a low-temperature cooling circuit).

[0028] Specifically, the second cooling circuit 16 is intended to cool at least the motor 12 and the power electronic devices 18 associated with the motor 12 by circulating at least one second coolant.

[0029] According to the present invention, the second cooling circuit 16 includes at least one heating radiator 20 (also commonly referred to as a unit heater) for heating the interior of the passenger compartment of the vehicle.

[0030] In an embodiment, the second coolant of the second cooling circuit 16 is in thermal contact with at least the charger 22 and / or the DC-DC converter 24 and / or the second motor 26, and with the motor 12 and the associated power electronic device 18.

[0031] The second cooling circuit 16 includes at least one degassing tank 28, which in this example is installed in parallel with the at least one heating radiator 20 (or unit heater).

[0032] Advantageously, the first cooling circuit 14 and the second cooling circuit 16 of the thermal engine are selectively in heat transfer contact via at least one water / water heat exchanger 30.

[0033] The first cooling circuit 12 (referred to as the high-temperature cooling circuit) and the second cooling circuit 16 (referred to as the low-temperature cooling circuit) of the thermal engine are advantageously separated from each other, wherein the first coolant flows in the first cooling circuit and the second coolant flows in the second cooling circuit.

[0034] In a manner known per se, the coolant used in vehicles is primarily composed of water, which forms the basis of the heat transfer fluid, and additives with, for example, antifreeze and / or anti-corrosion properties are advantageously added to the heat transfer fluid.

[0035] Preferably, the at least one water / water heat exchanger 30 is mounted such that it bypasses the second cooling circuit and is mounted on the bypass branch 31.

[0036] Advantageously, the water / water heat exchanger 30 allows heat to be transferred from the first cooling fluid of the heat engine 12 to the second cooling fluid, more specifically when the heat engine 12 is running.

[0037] The second cooling circuit 16 includes a control device 32 arranged upstream of the heat exchanger 30 for selectively controlling the flow of the second coolant in a bypass branch 31, the bypass branch including the at least one water / water heat exchanger 30.

[0038] Preferably, the control device 32 consists of a three-way valve.

[0039] In a variant not shown here, the water / water heat exchanger 30 includes an integrated control unit that is operated to selectively control the flow of the second coolant in the second cooling circuit 16.

[0040] In this variant, and unlike the embodiment shown in the accompanying drawings, the bypass branch 31 is eliminated, and the bypass function is directly integrated into the heat exchanger 30.

[0041] In a variant not shown here, the second cooling circuit 16 may not include this water / water heat exchanger 30.

[0042] Advantageously, in this case, an additional heating device is provided to compensate for the calories from the heat engine 12 that are not transferred via the water / water heat exchanger 30.

[0043] This additional heating device is integrated into a “heating, ventilation and air conditioning” system, which is also known by the acronym HVAC.

[0044] Preferably, the additional heating device of the HVAC system includes, for example, a heating element for heating air, specifically a self-adjusting heating element, such as a PTC ("positive temperature coefficient") resistor.

[0045] Advantageously, the second cooling circuit 16 includes a heating device 34, which is selectively controlled to heat the second coolant.

[0046] Heating device 34 includes, for example, a resistor for forming a boiler capable of heating a second coolant to a given setpoint temperature.

[0047] Advantageously, this heating device 34 can also be used to heat the first coolant in the first cooling circuit 14 of the thermal engine in order to specifically assist in the preheating of the thermal engine.

[0048] Then, in the opposite direction, heat transfer occurs from the second coolant to the first coolant of the heat engine through the water / water heat exchanger 30.

[0049] By heating the first coolant in this way, and using the second liquid heated by the heating device 34, friction can be advantageously reduced when starting the heat engine.

[0050] The heating device 34 is arranged upstream of at least one heating radiator 20 (or unit heater) for heating the interior of the passenger compartment of the vehicle.

[0051] The second cooling circuit 16 includes a temperature measuring device 36, which is used to measure the temperature of the second coolant.

[0052] Preferably, the device 36 for measuring the temperature of the second coolant is arranged upstream of the at least one heating radiator 20 and downstream of the heating device 34.

[0053] The second cooling circuit 16 includes at least one cooling radiator 38.

[0054] Advantageously, the second cooling circuit 16 includes a bypass branch 39 for bypassing the cooling radiator 38.

[0055] The second cooling circuit 16 includes a control device 40 (e.g., a three-way valve) arranged downstream of the cooling radiator 38.

[0056] Due to the control device 40 and the bypass branch 39, the second coolant may or may not pass through the cooling radiator 38.

[0057] Advantageously, the control device 40 is configured such that the second coolant does not pass through the cooling radiator 38, in order to retain the calories of the second coolant, thereby using some or all of the calories to perform another function instead of just heating the passenger compartment of the vehicle.

[0058] This could be the case, for example, when the vehicle is used in very low outside temperatures (i.e., under extremely cold conditions).

[0059] Specifically, the calories present in the second coolant can also be used, for example, to heat the high-voltage battery associated with the electric motor.

[0060] In the embodiment shown in a single figure, the second cooling circuit 16 includes a cooling loop 42 for cooling at least one battery 44 (referred to as a high-voltage battery) associated with the motor 12 via the second coolant.

[0061] For example, it can cause a second coolant to flow in this cooling loop 42 of the high-voltage battery 44.

[0062] Preferably, the cooling loop 42 of the high-voltage battery 44 includes at least one cooler 46.

[0063] Preferably, the cooling loop 42 of the high-voltage battery 44 includes at least one circulator 48, which is arranged between the cooler 46 and the at least one high-voltage battery 44.

[0064] Advantageously, the cooling loop 42 of the high-voltage battery 44 includes a control device 50, which is selectively controlled to control the flow of coolant therein.

[0065] The control device 50 of the cooling loop 42 is, for example, a three-way valve.

[0066] Specifically, the control device 50 allows the second coolant to flow selectively between the loop 42 and the second cooling circuit 16. Depending on the position of the control device 50, the cooling loop 42 can be isolated from the second cooling circuit 16, and the flow can be interrupted.

[0067] In this embodiment, the cooling loop 42 of the high-voltage battery 44 is connected to the second cooling loop 16.

[0068] In a variant not shown here, the cooling loop 42 of the high-voltage battery 44 is separate from the second cooling loop 16.

[0069] Preferably, the cooling loop 42 of the high-voltage battery 44 includes at least a temperature measuring device 52.

[0070] Advantageously, the temperature measuring device 52 is arranged downstream of the cooler 46, preferably downstream of the circulator 48 and upstream of the high-voltage battery 44, in order to measure the temperature of the second coolant in the loop 42.

[0071] Preferably, the second cooling circuit 16 includes at least one circulator arranged downstream of the cooling radiator 38.

[0072] Advantageously, the second cooling circuit 16 includes two circulators, namely a first circulator 54 and a second circulator 56.

[0073] In one embodiment, the first circulator 54 and the second circulator 56 are arranged in series downstream of the cooling radiator 38.

[0074] In one embodiment, two circulators 54 and 56 are arranged downstream of the control device 40 associated with the cooling radiator 38 and its bypass branch 39.

[0075] Two circulators 54 and 56 are arranged upstream of a section of a second cooling circuit 16, which includes the at least one motor 12 and associated power electronics 18.

[0076] The embodiment shown in a single figure is provided as a non-limiting example of a heat management system 10 according to the invention.

[0077] The industrial applicability of the present invention lies in relating to a thermal management system for a hybrid motor vehicle including at least one thermal engine and an electric motor 12, the system 10 including at least one first cooling circuit 14 for the thermal engine and a second cooling circuit 16 for at least cooling the electric motor 12 and associated power electronic devices 18, and characterized in that the second cooling circuit 16 includes at least one heating radiator 20 (or unit heater) for heating the interior of the vehicle's passenger compartment.

Claims

1. A thermal management system (10) for a hybrid electric vehicle including at least one thermal engine and one electric motor (12), said system (10) comprising at least: - A first cooling circuit (14), which is used to cool the vehicle's thermal engine by circulating at least one first coolant, and - A second cooling circuit (16) for cooling at least the motor (12) and the power electronic devices (18) associated with the motor (12) by circulating at least one second coolant. The second cooling circuit (16) is separate from the first cooling circuit (14) and includes at least one heating radiator (20) arranged in the second cooling circuit (16) for heating the interior of the passenger compartment of the vehicle.

2. The system as described in claim 1, characterized in that, The second cooling circuit (16) includes at least one degassing tank (28), which is installed in parallel with the at least one heating radiator (20).

3. The system as described in claim 1 or 2, characterized in that, The first cooling circuit (14) and the second cooling circuit (16) of the thermal engine are in selective heat transfer contact through at least one water / water heat exchanger (30).

4. The system as described in claim 3, characterized in that, The at least one water / water heat exchanger (30) is installed such that it bypasses the second cooling circuit (16).

5. The system as described in any one of claims 1 to 4, characterized in that, The second cooling circuit (16) includes a heating device (34) which is selectively controlled to heat the second coolant.

6. The system as described in claim 5, characterized in that, The heating device (34) is arranged upstream of the at least one heating radiator (20) used for heating the interior of the passenger compartment of the vehicle.

7. The system as described in any one of claims 1 to 6, characterized in that, The second cooling circuit (16) includes a device (36) for measuring the temperature of the second coolant.

8. The system as described in any one of claims 1 to 7, characterized in that, The second cooling circuit (16) includes at least one cooling radiator (38) and a branch (39) bypassing the at least one radiator (38).

9. The system as described in claim 8, characterized in that, The second cooling circuit (16) includes at least one circulator (54, 56) arranged downstream of the cooling radiator (38).

10. The system as described in any one of claims 1 to 9, characterized in that, The second cooling circuit (16) includes a cooling loop (42) for cooling at least one high-voltage battery (44) associated with the motor (12) by means of the second coolant.

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